The CPI(M) today expressed concern over Chhattisgarh government welcoming a US offer to assist in anti-Naxal operations and asked the Centre to warn the state government to desist from such a move.Two American diplomats offered to help the state government remove thousands of mines planted by Naxals and train its police force to battle the insurgents during their Thursday visit, B K S Ray, senior state official for home affairs, said today.Reacting to this offer the CPI(M) Politburo said in a statement: ‘‘The US has no business in involving itself in internal security and law and order issues. The attitude of the BJP state government is condemnable as no state government has the right to involve foreign countries in internal security matters.’’ The CPI(M) asked the Centre to immediately clarify the situation and ask the state government to desist from such activities.‘‘It should also convey to the US Embassy that such involvement in the politics and internal security matters of India is unacceptable,’’ the party said.A US Embassy spokesman denied the offer had been made, but said American officials had discussed law enforcement among other issues during the trip.David Kennedy said Washington was already coordinating with India in law enforcement and counter-terrorism. ‘‘All cooperation is coordinated at the federal level in New Delhi,’’ he said.